High-comfort, ultrathin air-layer nanofiber composite membrane for thermal insulation in complex environments

Abstract

Passive thermal management (PTM) materials have the ability of effectively inhibiting heat loss without consuming energy have great significance for thermal-insulting clothing. However, there is still a trade-off between high thermal insulation and small thickness, high durability, and general applicability. In this work, we develop a sustainable strategy for preparation of air-layer nanofiber composite (ALNC) membrane combining the electrospinning and stencil printing techniques. The ALNC membrane is comprised of two superhydrophobic TPU nanofiber membranes bonded by thermal expansion microspheres (TEMs) paste points with a stationary air-layer in the between. The obtained ALNC membrane shows a maximum temperature difference of over 18 °C when the testing stage temperature is 80 °C. It shows high wearing comfort performance, demonstrating a small thermal conductivity of 36.7 mW m⁻¹·K⁻¹, a high moisture permeability of 8.86 kg m⁻² d⁻¹, and a large air permeability of 21.31 mm s⁻¹. In particular, it has high durability against mechanical deformation and high applicability in complex environments (e.g., raining, high humidity, wind blowing). This work can provide fresh perspectives on the design and advancement of thermal-insulating nanofiber products.